UNUSUALLY high temperatures in the Arctic and heavy rains in the tropics are thought to have driven a global increase in atmospheric methane in 2007 and 2008 after a decade of near-zero growth, according to a new study.
Methane is the second most abundant greenhouse gas after carbon-dioxide, albeit a distant second.
NOAA scientists and their colleagues analysed measurements from 1983 to 2008 from air samples collected weekly at 46 surface locations around the world.
Their findings appeared in the September 28 print edition of the American Geophysical Union’s Geophysical Research Letters and are also available online.
One example of how dramatic methane escapes can be happened in Alaska during 2007.
A climate-change researcher, Katey Walter, brought a National Public Radio crew to Alaska’s North Slope, hoping to show them examples of what happens when methane is released when permafrost thaws beneath lakes.
When they reached their destination, Katey and the crew found even more than they had bargained for – a lake violently boiling with escaping methane.